Yi, XX , Acad Sinica, Inst Theoret Phys, POB 2735, Beijing 100080, Peoples R China.
部门归属:
Acad Sinica, Inst Theoret Phys, Beijing 100080, Peoples R China; NE Normal Univ, Inst Theoret Phys, Changchun 130024, Peoples R China; Univ Sci & Technol China, Dept Phys, Hefei 230026, Peoples R China; Univ Sci & Technol China, Ctr Nonlinear Sci, Hefei 230026, Peoples R China
英文摘要:
A quantum system is called separable if its density matrix can be written as a mixture of product stares. In this paper we apply the separability criterion as well as the distillability criterion to show that any initial inseparable 2 x 2 system retains its inseparability after its transmission through a noisy channel which consists of a set of harmonic oscillators. Hence the final state of the system can be distilled to a singlet form. For higher dimensions, however, this result is no longer true in general. The distillability of a state with higher dimensions after its transmission through the noisy channel is also discussed in this paper.